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Commit b44886c5 authored by Song Liu's avatar Song Liu Committed by Shaohua Li
Browse files

md/r5cache: call mddev_lock/unlock() in r5c_journal_mode_set 



In r5c_journal_mode_set(), it is necessary to call mddev_lock()
before accessing conf and conf->log. Otherwise, the conf->log
may change (and become NULL).

Shaohua: fix unlock in failure cases

Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 81fe48e9

drivers/md/raid5-cache.c

+15 −6
Original line number Diff line number Diff line
@@ -2540,23 +2540,32 @@ static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page) 
 */

int r5c_journal_mode_set(struct mddev *mddev, int mode)

{

	struct r5conf *conf = mddev->private;

	struct r5l_log *log = conf->log;



	if (!log)

		return -ENODEV;

	struct r5conf *conf;

	int err;



	if (mode < R5C_JOURNAL_MODE_WRITE_THROUGH ||

	    mode > R5C_JOURNAL_MODE_WRITE_BACK)

		return -EINVAL;



	err = mddev_lock(mddev);

	if (err)

		return err;

	conf = mddev->private;

	if (!conf || !conf->log) {

		mddev_unlock(mddev);

		return -ENODEV;

	}



	if (raid5_calc_degraded(conf) > 0 &&

	    mode == R5C_JOURNAL_MODE_WRITE_BACK)

	    mode == R5C_JOURNAL_MODE_WRITE_BACK) {

		mddev_unlock(mddev);

		return -EINVAL;

	}



	mddev_suspend(mddev);

	conf->log->r5c_journal_mode = mode;

	mddev_resume(mddev);

	mddev_unlock(mddev);



	pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",

		 mdname(mddev), mode, r5c_journal_mode_str[mode]);